t=0:pi/20:2*pi;
[x,y,z]= cylinder(2+sin(t),30);
subplot(2,2,1);
surf(x,y,z);
subplot(2,2,2);
[x,y,z]=sphere;
surf(x,y,z);
subplot(2,1,2);
[x,y,z]=peaks(30); 
surf(x,y,z);
